title: Aurintricarboxylic acid inhibits endothelial activation, complement activation, and von Willebrand factor secretion in vitro and attenuates hyperacute rejection in an ex vivo model of pig-to-human pulmonary xenotransplantation.
abstract: BACKGROUND
  In the xenotransplantation of vascularized organs, such as the lung, a large area of endothelial cell layer is a big hurdle to be overcome. We investigated the potential protective effect of aurintricarboxylic acid (ATA), a known inhibitor of platelet adhesion, on endothelial damage induced by xenogeneic serum. We also assessed its role in hyperacute xenograft rejection using a porcine ex vivo lung perfusion model.
  
  
  METHODS
  Porcine endothelial cells were incubated with human serum and other inflammatory stimuli. For the evaluation of von Willebrand factor (vWF) secretion and tissue factor (TF) expression, we used human endothelial cells. E-selectin expression, complement activation, TF expression and platelet activation were investigated by flow cytometry. In an ex vivo porcine lung perfusion model, the porcine lungs were perfused with fresh human whole blood: unmodified blood (n = 5), ATA-treated blood (n = 5), and ATA and lepirudin-treated blood (n = 5).
  
  
  RESULTS
  Aurintricarboxylic acid significantly inhibited TNF-alpha- or lipopolysaccharide-induced endothelial E-selectin expression in a dose-dependent manner. ATA also prevented human serum induced-E-selectin expression and human monocytic cell adhesion to porcine endothelial cells. Moreover, ATA abolished thrombin-induced vWF secretion as well as complement activation. However, ATA induced endothelial TF expression and platelet activation in vitro. In ex-vivo experiments, ATA treatment improved pulmonary function and attenuated sequestration of leukocytes. Although ATA did not influence thrombin generation, we were able to minimize its activity by adding lepirudin to the blood with ATA.
  
  
  CONCLUSIONS
  Our study demonstrated in vitro protective effect of ATA on the inhibition of endothelial activation and vWF secretion and confirmed detrimental effect of ATA on induction of endothelial TF and platelet activation. The combination of ATA and lepirudin may act beneficially by preventing coagulation perturbation while maintaining improved xenograft survival.
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hyun Kyung
authors.initials: HK
authors.lastname: Kim
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Kim
authors.forename: Hyun Cho
authors.initials: HC
authors.lastname: Wi
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Lee
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Kim
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Kang
authors.forename: Young Tae
authors.initials: YT
authors.lastname: Kim
mesh_terms: D000818:Animals; D001312:Aurintricarboxylic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D002478:Cells, Cultured; D003167:Complement Activation / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects; D006084:Graft Rejection / Q000276:immunology / Q000503:physiopathology / Q000517:prevention & control*; D006629:Hirudins / Q000008:administration & dosage; D006801:Humans; D066298:In Vitro Techniques; D016040:Lung Transplantation / Q000009:adverse effects* / Q000276:immunology* / Q000502:physiology; D010477:Perfusion; D015539:Platelet Activation / Q000187:drug effects; D011994:Recombinant Proteins / Q000008:administration & dosage; D013552:Swine; D014183:Transplantation, Heterologous; D014841:von Willebrand Factor / Q000378:metabolism
chemical_list: D006629:Hirudins; D011994:Recombinant Proteins; D014841:von Willebrand Factor; D001312:Aurintricarboxylic Acid; C083544:lepirudin